|
|
@@ -9,39 +9,45 @@ using System;
|
|
|
using Microsoft.Xna.Framework;
|
|
|
using Microsoft.Xna.Framework.Content;
|
|
|
using Microsoft.Xna.Framework.Graphics;
|
|
|
+using System.Threading.Tasks;
|
|
|
+using Microsoft.Xna.Framework.Input;
|
|
|
|
|
|
|
|
|
namespace NetworkStateManagement
|
|
|
{
|
|
|
/// <summary>
|
|
|
/// When an asynchronous network operation (for instance searching for or joining a
|
|
|
- /// session) is in progress, we want to display some sort of busy indicator to let
|
|
|
- /// the user know the game hasn't just locked up. We also want to make sure they
|
|
|
- /// can't pick some other menu option before the current operation has finished.
|
|
|
- /// This screen takes care of both requirements in a single stroke. It monitors
|
|
|
- /// the IAsyncResult returned by an asynchronous network call, displaying a busy
|
|
|
- /// indicator for as long as the call is still in progress. When it notices the
|
|
|
- /// IAsyncResult has completed, it raises an event to let the game know it should
|
|
|
- /// proceed to the next step, after which the busy screen automatically goes away.
|
|
|
- /// Because this screen is on top of all others for as long as the asynchronous
|
|
|
- /// operation is in progress, it automatically takes over all user input,
|
|
|
- /// preventing any other menu entries being selected until the operation completes.
|
|
|
+ /// session) is in progress, this screen displays a busy indicator and blocks input.
|
|
|
+ /// It monitors a Task<T> returned by the async call, showing the indicator while
|
|
|
+ /// the task is running. When the task completes, it raises an event with the
|
|
|
+ /// operation result (or null on failure), then automatically dismisses itself.
|
|
|
+ /// Because this screen sits on top while the async operation is in progress, it
|
|
|
+ /// captures all user input to prevent interaction with underlying screens until
|
|
|
+ /// the operation completes.
|
|
|
/// </summary>
|
|
|
- class NetworkBusyScreen : GameScreen
|
|
|
+ class NetworkBusyScreen<T> : GameScreen
|
|
|
{
|
|
|
-
|
|
|
- IAsyncResult asyncResult;
|
|
|
+ readonly Task<T> task;
|
|
|
+ readonly System.Threading.CancellationTokenSource cts;
|
|
|
+ bool completionRaised;
|
|
|
Texture2D gradientTexture;
|
|
|
Texture2D catTexture;
|
|
|
|
|
|
- public event EventHandler<OperationCompletedEventArgs> OperationCompleted;
|
|
|
+ event EventHandler<OperationCompletedEventArgs> operationCompleted;
|
|
|
+ public event EventHandler<OperationCompletedEventArgs> OperationCompleted
|
|
|
+ {
|
|
|
+ add { operationCompleted += value; }
|
|
|
+ remove { operationCompleted -= value; }
|
|
|
+ }
|
|
|
|
|
|
/// <summary>
|
|
|
/// Constructs a network busy screen for the specified asynchronous operation.
|
|
|
+ /// Accepts a Task<T> representing the in-flight operation.
|
|
|
/// </summary>
|
|
|
- public NetworkBusyScreen(IAsyncResult asyncResult)
|
|
|
+ public NetworkBusyScreen(Task<T> task)
|
|
|
{
|
|
|
- this.asyncResult = asyncResult;
|
|
|
+ this.task = task;
|
|
|
+ this.cts = null;
|
|
|
|
|
|
IsPopup = true;
|
|
|
|
|
|
@@ -49,6 +55,19 @@ namespace NetworkStateManagement
|
|
|
TransitionOffTime = TimeSpan.FromSeconds(0.2);
|
|
|
}
|
|
|
|
|
|
+ /// <summary>
|
|
|
+ /// Overload that accepts a CancellationTokenSource to allow user cancellation.
|
|
|
+ /// </summary>
|
|
|
+ public NetworkBusyScreen(Task<T> task, System.Threading.CancellationTokenSource cts)
|
|
|
+ {
|
|
|
+ this.task = task;
|
|
|
+ this.cts = cts;
|
|
|
+
|
|
|
+ IsPopup = true;
|
|
|
+
|
|
|
+ TransitionOnTime = TimeSpan.FromSeconds(0.1);
|
|
|
+ TransitionOffTime = TimeSpan.FromSeconds(0.2);
|
|
|
+ }
|
|
|
|
|
|
/// <summary>
|
|
|
/// Loads graphics content for this screen. This uses the shared ContentManager
|
|
|
@@ -64,35 +83,60 @@ namespace NetworkStateManagement
|
|
|
catTexture = content.Load<Texture2D>("cat");
|
|
|
}
|
|
|
|
|
|
-
|
|
|
-
|
|
|
-
|
|
|
-
|
|
|
/// <summary>
|
|
|
- /// Updates the NetworkBusyScreen.
|
|
|
+ /// Updates the NetworkBusyScreen, checking whether the underlying Task has
|
|
|
+ /// completed and raising OperationCompleted when it does.
|
|
|
/// </summary>
|
|
|
public override void Update(GameTime gameTime, bool otherScreenHasFocus,
|
|
|
bool coveredByOtherScreen)
|
|
|
{
|
|
|
base.Update(gameTime, otherScreenHasFocus, coveredByOtherScreen);
|
|
|
|
|
|
+ // Optional: allow user to cancel (Esc or B)
|
|
|
+ if (!completionRaised && cts != null)
|
|
|
+ {
|
|
|
+ var kb = Keyboard.GetState();
|
|
|
+ if (kb.IsKeyDown(Keys.Escape))
|
|
|
+ {
|
|
|
+ cts.Cancel();
|
|
|
+ }
|
|
|
+ var gp = GamePad.GetState(PlayerIndex.One);
|
|
|
+ if (gp.IsConnected && gp.IsButtonDown(Buttons.B))
|
|
|
+ {
|
|
|
+ cts.Cancel();
|
|
|
+ }
|
|
|
+ }
|
|
|
+
|
|
|
// Has our asynchronous operation completed?
|
|
|
- if ((asyncResult != null) && asyncResult.IsCompleted)
|
|
|
+ if (!completionRaised && task != null && task.IsCompleted)
|
|
|
{
|
|
|
- // If so, raise the OperationCompleted event.
|
|
|
- if (OperationCompleted != null)
|
|
|
+ object resultObject = default(T);
|
|
|
+ Exception error = null;
|
|
|
+ try
|
|
|
+ {
|
|
|
+ // Accessing Result will throw if the task faulted/canceled.
|
|
|
+ // We catch here and allow handlers to present error UI.
|
|
|
+ resultObject = task.Result;
|
|
|
+ }
|
|
|
+ catch (Exception ex)
|
|
|
{
|
|
|
- OperationCompleted(this,
|
|
|
- new OperationCompletedEventArgs(asyncResult));
|
|
|
+ // Leave result as default (usually null) to signal failure to handlers.
|
|
|
+ error = (task?.Exception?.GetBaseException()) ?? ex;
|
|
|
}
|
|
|
|
|
|
- ExitScreen();
|
|
|
+ var handler = operationCompleted;
|
|
|
+ if (handler != null)
|
|
|
+ {
|
|
|
+ handler(this, new OperationCompletedEventArgs(resultObject, error));
|
|
|
+ }
|
|
|
|
|
|
- asyncResult = null;
|
|
|
+ completionRaised = true;
|
|
|
+ // Clear handlers to avoid reentry if this screen lingers during transition off
|
|
|
+ operationCompleted = null;
|
|
|
+ ExitScreen();
|
|
|
}
|
|
|
}
|
|
|
|
|
|
-
|
|
|
/// <summary>
|
|
|
/// Draws the NetworkBusyScreen.
|
|
|
/// </summary>
|
|
|
@@ -148,7 +192,5 @@ namespace NetworkStateManagement
|
|
|
|
|
|
spriteBatch.End();
|
|
|
}
|
|
|
-
|
|
|
-
|
|
|
}
|
|
|
}
|
Dominique Louis